在两个固体二酸体上摄入气态胺的明显温度趋势
Yixin Li1, Pascale S J Lakey1, Michael J Ezell1
1Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States.
概括
在固体酸上测量了n-丁胺的吸收系数. 一种新的离子液层机制解释了谷氨酸的异常温度趋势,改善了大气化学模型.
科学领域:
- 大气化学 大气化学
- 化学动力学 化学动力学
- 表面科学是一门学科.
背景情况:
- 了解气体表面相互作用对于大气化学至关重要.
- 微量气体的反应性吸收会影响气溶的特性和气候.
- 之前的模型往往简化了复杂的温度依赖反应路径.
研究的目的:
- 在广泛的温度范围内测量n-丁胺 (BA) 对酸 (SA) 和谷氨酸 (GA) 的吸收系数.
- 阐明这些相互作用的反应机制和温度依赖性.
- 为了验证气溶表面和散装化学 (KM-SUB) 的动力多层模型.
主要方法:
- 使用了结合Knudsen电池和温度调节的脱吸装置.
- 在固体SA和GA上测量了BA的吸收系数,从298K到177K.
- 使用KM-SUB模型分析实验数据.
主要成果:
- 在SA上的吸收系数随着温度下降而单调增加,与表面反应一致.
- 在GA上的吸收系数显示了一个不寻常的趋势:随着温度的下降而增加,然后下降.
- 对GA的不寻常趋势归因于离子液 (IL) 层的形成,影响BA脱吸和扩散/反应速率.
结论:
- 这项研究揭示了BA对SA和GA的独特反应机制.
- 在GA上形成IL层显著改变了吸收的温度依赖性.
- KM-SUB模型成功地重现了观察到的独特趋势,提高了气溶化学的预测能力.
相关概念视频
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3.3K
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
3.3K
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2.4K
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
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Physical Properties of Carboxylic Acid Derivatives
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Intermolecular forces dictate several physical properties such as boiling points, melting points, solubilities, and so forth. They are classified into four types: ionic forces, hydrogen bonds, dipole–dipole forces, and dispersion forces. Ionic forces are the strongest, while dispersion forces are the weakest.
Among the carboxylic acid derivatives, the boiling points of acid chlorides and esters are very similar and are the lowest in the series. Acid anhydrides have slightly higher boiling...
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Acid Halides to Amides: Aminolysis
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In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
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1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
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Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
3.7K
2° Amines to N-Nitrosamines: Reaction with NaNO2
4.1K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
4.1K


